@Anthony Nguyen, I use many applications both on a pc as well as iPhone/iPad. First off, I use everything by Google(it just works). My email, contacts, map, browser & calendar are all Google based. I also use most Microsoft applications such as Outlook, MS Office, etc. via my desktop pc.
For my mobile devices, I use many applications such as the ones listed above, plus the following:
Docusign - used for paperless document/contract/tenant form signings.
Apps such as PDF Expert(pdf doc modifier) , PDF Office(pdf doc creator) , PDF Converter, Spark Email, Documents(cloud doc integrator), Calendar 5, Scanner Pro, Printer Pro all created by a company by the name of Readdle. The name of these apps are self explanatory( I believe) and they all work together to make my business processes work alot smoother. For more details about what these apps do, just checkout there website.
I use a project manager app called IQTELL.
My favorite CRM that I'm using is called Nimble. It's the best social media connected CRM that I have found, if you are into that type of thing.
Current property management app that I use is called RentecDirect.
There are so many other apps that I can list, but, these are just a few that help my business work and make my life alot easier. Hope this helps.
I'm a buy & hold investor so my need for software may not be as high as some other folks. Gmail and Google Calendar are definitely must-halves. If you're going to use Gmail and have an iPhone/iPad, download their app instead of using the built-in mail, I like it better (also can try Google Inbox).
I have my Google Calendar synced to my iPhone's calendar, and Google Contacts synced to my phone as well, so looking up people's contact details is a breeze.
And finally, I now do all of my property analysis, projections, comparison on my phone. I used to use Excel, but it just didn't scale well and I couldn't export PDF reports.