For several years I’ve used ShoeBoxed (a web app/service) to scan my receipts so that I can verify each transaction from ShoeBoxed with each Tiller transactions that should have a receipt. Shoeboxed generates a convenient web link to each receipt that you snapshot with their handy app, and I paste that web link into Tiller. It’s convenient to be looking through Tiller and then have a quick link to visually examine any receipt.
This is easy to process at any scale. Just create a “transformation” tab in your Tiller spreadsheet that has two areas: the first area accepts the data from ShoeBoxed in their standard arrangement, and the second area shows that data reflected back in a way that you can quickly copy/paste it to the bottom of your main Tiller transactions tab. Basically, the second area uses spreadsheet links that reference back to the first area which accepts the raw data.
After pasting the new data to the bottom of the Tiller transactions tab, then sort all transactions by date so that Tiller and ShoeBoxed transactions are adjacent. Then go through and visually compare the paired consisting of Tiller AND ShoeBoxed. Use this opportunity to copy/paste the receipt web page link from the ShoeBoxed version of the transaction into the Tiller representation of the transaction. When you are done, delete all the Shoeboxed transactions, as they no longer serve any purpose. Now your Tiller transactions have been cross-checked against receipts, and you are left with a nifty Webb link reference to a picture of your receipt.