Herwe are some suggestions to try:
App Store which only offers open source apps that are free, have no advertisements and no dependencies. Even though the number of apps is limited - speak it has huge gaps - there are some aps that are unique and hard to find elsewhere. Truly worth a look.
2. K-9 Mail
(download from F-Droid)
The icon is a bit silly but don't be mislead, it's one of the best email apps out there. I was surprised in view of K-9 not being not bigger than the stock app but so much more customizable.
3. Notify Lite
(download from F-Droid)
The app provides unified status bar icon notifications, Led notifications, pop-up windows and vibration notifications for email, sms and calendar events, a pro version also for Twitter and Facebook. The "Lite" in the name is a joke, bcs. the options to customize and tailor notifications and reminders are overwhelming. But once adjusted it works like a charm for me. It does not have a big memory foot-print, and reminders work flawless with Stamina mode on, which is not certain with some other apps. F-Droid said the app will bug me with in-app purchases requests, but 1., the Pro features offered are not needed for everyone, and 2., I don't feel pestered at all, it is still done in a very decent way.
4. Evolve SMS
If you are looking for a more modern SMS app, or if you are sick of sms integration in Hangout, than Evolve may be just the ticket. It is an Sms app with beautiful style plus easy functionality. The sliding conversations are no comparison to the boring stock sms app system (seems they want to out-phase SMS, so making the SMS apps boring is one way of teaching people to use something else). The widget is really useful - and I am saying that even though I usually avoid widgets. On Play some people commented Evolve being slow and lagging. On my V Evolve is not slow at all. May be the remark is with regards to an older version. I can well imagine an email app of the same style, or even both functions sms and email integrated. The only thing I don't care for is the picture banner on top of each conversation, suggest to make it a simpler graphic element. Thanks to the developer! I was first hesitant bcs Evolve is much bigger than my stock messaging app (I am usually trying to avoid that, too). Now I am glad I tried it. Look here http://forum.xda-developers.com/show....php?t=2608958
As for a calendar app I am still using the modded Google calendar. I haven't found anything better. Everything I tried is either not a standalone calendar, which means I still need the Android, Sony or Google calendar installed and working. Or, syncing does not really work reliable. I got to say the chapter calendar apps is a pretty sad chapter in the book of Android apps.
"I don't think we need comments/discussions on rules/guidelines."