I tried this out yesterday and it looks very nice and is pretty quick.

After adding some wallets, I ran into a couple of issues.  Not sure if they can be resolved easily, or I am just missing something?

1.  you can only add 5 wallets.
     i have 20 (am sure it will incrrese over time) per coin that i play with - I do not have that much volume, but I do not like to keep all eggs in one basket
2.  How can I add historical data?
     I can either enter 5 wallets OR a fixed amount.
     e.g. I bought some OMG, but they cannot give me the public address, as you cannot send OMG back to them.
     what I would need would be some way to say "I bought 5 OMG on the 06/02/2018 and I transferred them to my private wallet on the 15/02/2018"
     Then I would enter my wallet as well and the calculations could continue from there.
     Currently, the charts start on the day i transferred my coins to my private wallet and state a 0% gain, even though some increased by 12% from when i bought them
3.  I think someone already mentioned it, but a current value per wallet would also be great.
     At the moment it just shows me number of coins in that wallet.

Getting that in there would help a lot.