# Bitcoin wallet simulator: build a BTC screen that survives a close-up Source: https://flexdger.com/blog/bitcoin-wallet-simulator Updated: 2026-11-07 Published: 2026-09-23 Topic: Crypto wallet mockups (https://flexdger.com/blog/crypto-wallets) > How a Bitcoin wallet simulator composes a believable BTC screen for videos and demos: decimals, live price math, the 24h line, and where paper trading differs. A convincing Bitcoin screen is mostly arithmetic: a quantity with the right number of decimals, a dollar value that follows the price, and a daily change whose two numbers agree. Here is how to build one, and how it differs from paper trading and testnet wallets. **Short answer:** A Bitcoin wallet simulator turns a quantity you type into a BTC wallet screen: up to eight decimals, a dollar value tied to the live price and a 24h change that adds up. Flexdger Wallet is one. It is a mockup for videos, demos and lessons, not a paper-trading app, not a testnet wallet and not a hardware wallet, and it never proves a balance. ## Start with the decimals People rarely hold whole bitcoins, so the quantity on a believable screen is a fraction. The unit is split into eight decimals, and the smallest piece, the satoshi, is 0.00000001 BTC. Take a price near $64,000 (an illustrative figure, not a quote): one satoshi is worth $0.00064, and a dollar buys about 1,562 of them. That drives what a plausible quantity looks like. A purchase of $500 at that price is 0.0078125 BTC, and the exchange fee nudges it to something untidy. A bigger position might read 0.27184190 BTC, which is 27,184,190 sats. Round values like 0.25 BTC exist, but they look chosen. In a list row the quantity can be shortened to five decimals (0.27184 BTC) and lose almost nothing, since 0.00001 BTC is $0.64 at that price. ## The dollar value is computed, so it moves The fiat amount beside the quantity is a product, not a field: 0.27184190 × $64,000 = $17,397.88. In our simulator BTC is one of five built-in tokens with real market prices refreshed every 4 seconds, and the quantity is the only number you enter. So the row is never still. Let the price tick to $64,010.50 and the same holding reads $17,400.74, up $2.85. On a recording, that small drift is what makes the screen feel like software ([why live prices change how a mockup reads](https://flexdger.com/blog/larp-wallet-tutorial#record)). On a still image, the cents are whatever the market left behind. To total a whole portfolio at live prices, the [crypto portfolio calculator](https://flexdger.com/tools/crypto-portfolio-calculator) handles 22 coins. Three quantities and what they read as at $64,000: - **0.0150 BTC** is $960.00, a modest everyday holding. - **0.8 BTC** is $51,200.00, a serious position. - **0.00042 BTC** is $26.88, a pocketful of 42,000 sats. ## Two numbers on the 24h line must agree A daily change is a percentage and a dollar amount, and one fixes the other. The percentage is measured on yesterday’s value, which means the dollar change is value minus value divided by (1 + pct). An example. The row is worth $17,397.88 and BTC is up 1.80% on the day. Yesterday it was worth 17,397.88 / 1.018 = $17,090.26, so the change is +$307.62. A shortcut that takes 1.80% of today’s value gives $313.16, which overshoots by $5.54, and a careful viewer will notice. Now add $950.20 of cash. The header total becomes $18,348.08 and the header change stays +$307.62, because the cash did not move. Yesterday’s total was $18,040.46, so the header percentage is +1.71%, lower than the 1.80% on the BTC row. A header that repeats 1.80% is wrong. A longer worked list is in [how a mockup balance is composed](https://flexdger.com/blog/portfolio-wallet-simulator#balance). ## What a real Bitcoin wallet has that a mockup lacks A one-coin screen is simpler than a [multichain wallet mockup](https://flexdger.com/blog/portfolio-wallet-simulator#several-chains), yet a real Bitcoin wallet shows things no composition can supply: - **A receive address**, frequently beginning with bc1, that anyone can look up. - **Confirmations**, the number of blocks that have sealed a payment, starting at zero while it waits. - **Network fees**, quoted in sats per virtual byte and driven by demand at the moment of sending. - **A history you can verify**, where each line carries a transaction ID that opens on a block explorer. The simulator offers none of these in a form an explorer could confirm. It talks to no chain, never requests a private key or seed phrase, and cannot sign or send. Nor is it a hardware wallet; that device has [its own simulator page](https://flexdger.com/blog/hardware-wallet-simulator). ## Other tools that answer to the same search As of October 28, 2026, a search for a Bitcoin wallet simulator turns up three different kinds of tool. Pick by the outcome you want. - **A screen for a video, skit, deck or demo:** a wallet screen simulator such as this one. You type a BTC quantity, the price is live, there are no keys and no chain. - **Practice at buying and selling with pretend money:** a paper-trading app, which keeps virtual cash and moves your balance with your trades. - **Testing real wallet software:** a testnet wallet, which runs on a test network with valueless coins and is aimed at developers. The comparison between these is in [demo account, paper trading or wallet simulator](https://flexdger.com/blog/crypto-wallet-simulator#demo-account). The paper-trading apps that rank first are good at their job, and none draws a wallet mockup. Details below come from each product’s own page. - **CustomCrypto: Crypto Simulator (App Store).** Learn with virtual money at real market prices, 35+ coins, portfolio charts and profit and loss, no sign-up. No upfront price, a Premium purchase, 4.5 from 26 ratings (read October 28). - **CryptoPlay: trade simulator (App Store).** Practice buying, selling and converting with virtual money; the listing says no real trades are made and balances cannot become real money. No upfront price, two upgrade levels, 5.0 from 6 ratings (read October 28). - **Crypto Trading Simulator (Google Play).** Paper trading from $1,000 of virtual money, real-time prices and a leaderboard, labeled education only. 50K+ downloads, 4.6 from 716 ratings (read October 12). - **TradingView paper trading.** A demo account for practice with no deposits and no real money; its page calls it a simulator with no risk and no fees. What a wallet simulator contributes is the other half: the balance header, a BTC row and a day change that you can film on a phone, with no orders and no score. Flexdger Wallet is such an app, made by us, a paid web app you add to your home screen. Anyone who wants to practice trading will be better served by the list above. ## What the finished image cannot prove Nothing about anyone’s holdings. Real prices applied to a typed quantity produce a typed total, and tidy 24h arithmetic only shows the sums were done. No real address, no transaction ID and no confirmations means an explorer has nothing to check, which is precisely why a screenshot is never evidence. Our terms of use forbid presenting the screen as an account statement or proof of funds. If someone sends you a BTC screenshot, [the tells of a composed wallet screenshot](https://flexdger.com/blog/spot-a-fake-crypto-wallet-screenshot) are a start, but only an address on an explorer plus a signed message settles the question. Used for what it is, a Bitcoin screen in a lesson, a deck or an explainer video, the composition only needs to read right. The same work on a SOL-first screen, with SPL tokens, is in [the Solana wallet simulator](https://flexdger.com/blog/solana-wallet-simulator). ## Questions ### Why does the dollar value on a BTC row keep changing? Because it is not typed. It is your quantity multiplied by the market price, and in Flexdger Wallet the price of the five built-in tokens, BTC among them, refreshes every 4 seconds while the phone is online. You only choose the quantity. ### What is the smallest piece of bitcoin? One satoshi, written 0.00000001 BTC, so a coin splits into 100 million of them. Real balances therefore tend to end in digits nobody picked. A row may be shortened to five decimals, because 0.00001 BTC is worth well under a dollar at recent prices. ### Can I practice trading Bitcoin with it? No. It has no orders, no trades and no score. If you want to practice buying and selling with pretend money, use a paper-trading app; the ones that rank for this search are listed in the comparison below. ### How do I compute a 24h dollar change from a percentage? Divide today’s value by one plus the percentage to get yesterday’s value, then subtract. A row of $17,397.88 that is up 1.80% was worth $17,090.26 yesterday, so it gained $307.62, not the $313.16 you get by taking 1.80% of today’s figure. ### Does the simulator install like a normal app? It is a paid web app that you add to your home screen, so there is no APK and no IPA, and nothing goes through a store. It never asks for a private key or a seed phrase.