The piggy bank symbol on the bottom menu of the app opens the Deposit Dashboard.
There you can see the total amount of coins you have earned, in the section "Coins Invested".
Then in the section "Investor Level" you can see the interest percentage of your investment and your investor level.
You can upgrade your investor level from there by completing the relevant task that is given to you for that purpose.
The last section displays your next accrual date, meaning, how many days until your next accrual and how many coins you get according to your current interest rate.