I would just add that I think some people may not realize how unique Pop Peeper actually is as compared to most apps. In general apps will typically progress via updates with relatively minimal options offered to their users to retain what existed previously as they progressively upgrade. Pop Peeper on the other hand offers many choices that offer users a multiplicity of variations that can be applied to the app. For starters, the choice is there to add the Plus Pack and/or go with Pro or to alternatively go with neither. Just the various ways to be notified of email are as we know substantially numerous indeed. The level of settings available is exemplified by the large number of tabs in Pop Peeper options alone with all the numerous optional settings provided in each specific tab not to mention all that PPtweaker optionally offers in number of tabs and all the settings provided for each of these tabs as well. Of course the more flexibility provided the user to make choices increases the difficulty to support the complexity of doing so.
Of course I could go on and on as I'm barely covering the myriad of user options available so perhaps the the tool bar alone speaks to the point I'm making. The ability to add/remove virtually anything I want to the PP toolbar alone exemplifies the flexibility that Pop Peeper provides. I use very few apps, in fact Pop Peeper is one of a very few, but if I recall over the years correctly most apps in general do not offer nearly the flexibility that Pop Peeper does.

- I can do virtually anything I want with this toolbar
This is not to suggest the example here begins to represent how configurable Pop Peeper actually is, but as the old adage goes sometimes "a picture can be worth than a 1000 words". As we know, I can "customize" this toolbar virtually anyway I want (add/remove/position) and there are nearly as many options as I am using that are still available that I'm not using. I posted this because I think it serves as an excellent example of the vast flexibility that Pop Peeper provides.
Of course for the most part I'm essentially preaching to the choir as most are fully aware of all of this, but I just felt it worth mentioning for the few who may be overlooking some of what I've mentioned.
Good judgment comes from experience and a lot of that comes from bad judgment. - Will Rogers