There are a lot of spreadsheets and apps floating around for tracking a 5/3/1 workout plan, but this one is by far the best. Easy to use, not confusing like many other apps.
Be aware that in order to select custom accessory work (which is basically a must in my opinion) you need to pay a small fee, but that’s a totally fair price to pay on my opinion.
All that said, there’s one feature I’d love to see. I’d love to see a way to track weight in the accessory work so I can easily see how much I lifted last time and track how my accessory lifts progress over time. Right now I just write the weight in the notes, but I’d love a dedicated way to input it, and I’d love a display on the accessory lifts that states how much weight you used last time you did that lift,