Hi @Jasper_Verbunt - happy to shed light on the options available to tailor your Retool apps to end-user use cases. Overall, the top-level answer is that to fully meet your use case, the features you're likely looking for tend to be on the higher tier plans.
Specific to your question, around hiding the quick menu with the Retool logo on it in the left bottom of the page, the only way to do so is to use custom branding. Custom branding is available on Business/Enterprise plans, although based on my testing outlined here, it's only possible to hide the Retool logo if you're on Enterprise.
Granular permissions controls are available on the Business plan or above, so to ensure your end users can't edit the app, Business or Enterprise would give you that control.
More recently (as I think Kabirdas was hinting back in January!) we released new products, Retool Portals and Retool Embed, over the summer that could be a good fit for your use case. They're specifically meant for "external" apps that are used by people outside your company. Here are the docs to learn more!
- Quickstart tutorial: Portals
- Quickstart tutorial: Embedded apps
- Have more questions as you check these out? See if there're answers in our External Apps forum category - and if not, create a new topic to ask!
So lots of options - for example if you're willing to keep the little menu there, but want to customize branding colors/login screen logo/fav icon, and ensure users can't edit the app, you could use the Business plan. That would also allow you to leverage Portals or Embedded apps. If you don't mind users being able to click in to edit the app and don't want to try Portals/Embed, then you could still remain on a Free or Team plan.
Hope this info helps point you in a useful direction 