Just moved from Mint. Here is my advice: work on the UI
I needed a replacement for Mint. I was unsure between Simplifi and Monarch Money. I chose Simplifi merely because it is by Quicken, which has been around for a long time. I just finished adding all my accounts to Simplifi. So far, so good. Quicken Simplifi seems to be better than Mint at connecting with financial institutions and tracking investments. But it lags terribly behind Mint and Monarch on one key aspect: the interface.
In a financial tracking app, the interface is not an accessory, it is an essential part of the functionality. If you are trying to track your finances, you don't want the friction of having to read a poorly formatted column of numbers like the Simplicity online interface. Please get inspired or just outright copy the formatting in Mint or Monarch. The current interface is amateurish. Users do not get attached to software, they get attached to the interface.