Absolutely nothing. Coinomi is a free wallet.

But what are those fees I keep seeing? Do you charge me for accepting or sending payments?

No, we don't charge anything. Receiving coins is always free, fees are paid by the sender. Outgoing transactions require a transaction fee which goes to the miners of each coin, not to Coinomi. You can manually set a transaction fee by going to "... / Settings / Transaction fees".

Note that transaction fees directly impacts the time it will take for your transaction to be confirmed. Please consult the following links for more information: