I was using Simple as my primary bank, and their Goals feature made it possible to do envelope-style budgeting really conveniently. Unfortunately the bank that backed them, BBVA, sold to PNC. This lead to my Simple being shut down, and my account was converted first to a BBVA account and then to a PNC account.
When I lost access to the Simple app I first built myself a spreadsheet, and then started work on a webapp called Complex to replicate their functionality. Currently you have to enter all transactions manually, but I eventually plan to integrate with Plaid so I can automatically pull in transaction data. Without automatic transaction imports, I'd say Complex currently falls about halfway between the original Simple app and a spreadsheet in terms of convenience/ease-of-use.
I don't have any kind of business model for this, but if I eventually make it public I'll probably charge a monthly fee to allow automatic transaction imports so I can cover Plaid's fees. There's not much server load required to run something like this, so I expect I'll be able to keep server costs below $20/month even if I pick up a couple hundred active users.