We just added a very basic calculator function to our web app, so you can now use basic mathematical operations when entering a cost (addition, subtraction, multiplication, and division). We hope to add similar features to our mobile apps at some point in the future!
We’re definitely considering Bitcoin! We think cryptocurrencies are fascinating (seriously, we’ve held a Providence meet-up about them), and it’s something on our list of possible improvements for the future.
So sorry for the trouble! This is on our list of possible improvements for the future – I can’t say exactly when it’ll be added, but we know it’d be a useful improvement. In the meantime, our apologies for the inconvenience!Dark Dragon commented
Just give the same options as on mobile in the web interface!