I was thinking to develop a simple app for learning purpose. Upon doing research I found that a similar idea and process has already been patented. The idea is of a SaaS application that performs only one task/process and that task is [patented](https://patents.google.com/patent/US11144975B2). This idea sounded "un-patentable" to me but the fact is that several patents by same inventor exist for the same simple idea.

With regards to this patent and the patent process I don't understand following:

* will it be considered legal if I develop similar app but slightly different process that results in achieving the same goal? (however in this case there are not many ways to show a map with pins containing information in them so most likely it will look similar with different UI design)
* can my slightly modified process be patented by someone else?
* if modifications are allowed then how significant should they be?
* can I still develop the app for learning and share that code on github?
* how do other SaaS vendors get around patents as I see a lot of companies offering similar products? for example Amazon and Microsoft both provide cloud functions/lambdas so how do they avoid infringing patents?