For basic billing and invoices though, Square is great to have considering no monthly fee. (Albeit a bit higher processing of course.)
For pure accounting software, QuickBooks is hard to beat. :dblthumb2: Used it for 20 years for 3 different businesses. Having the integration with TurboTax makes it a no brainer as well!
Not sure how it'll work these days as contact management, which is where I prefer a CRM based platform.
Way back when... as in when CompuServe was THE place to go for tech support, manufacturer supported forums, and tons of user interest forums I was a forum Sysop for a couple different forums, (Audio as well as Video & Home Theater) and the forum sponsor managed to get me free software from a little company called Chaos Software. They have a nice CRM based platform that'll do all sorts of scheduling as well as e-mail of course. They have Time and Chaos that I used for years, then ended up with Intellect (it was free) which actually is the same thing, just has a business e-mail feature that T&C doesn't.
Of course these days you can get all sorts of (pay) options like cloud hosting, Outlook, Google, and Desktop sync options... and several other plug-in options.
But the one I use for my phone, and LOVE is Deja Office!

rops:
The modules are stunning in their ability to link, search, and find literally anything you could EVER want.
For instance...
Say you are looking for a professional building, or say a doctors office to setup an appointment. As soon as you start typing in the name of the place it'll pop up similar contacts as you type. Then when you move to "Location" and put in the name, it'll not only find it (generally just by the name) but it'll pull up a thumbnail from Google Maps, WITH a street view of the building!

If it doesn't find the place by name, then just insert a comma, then put in the first letter or two of the city and you'll get a list which probably has what you're looking for.
To test just now, I put in Autogeek and got three listings. Autogeek.net, Autogeek, and Autogeeks (in Waterford NJ). Then switched it up a bit and put in Animal Kingdom and instantly got Disney Animal Kingdom, then put in Lodge, and got Animal Kingdom Lodge, complete with a photo and map thumbnail. Click on the thumbnail and you can open Google maps to navigate there, or add the location as a new contact.
Pretty kewl! :dblthumb2:
Another thing that's cool about Deja Office is whenever you get a phone call on your cell, if you don't have that number as a contact it'll ask you to add it. Really like that feature as well.
Deja Office is FREE too, which makes it all that much better!
It will sync with pretty much all popular CRM platforms, from Google, to Outlook, and yes, even Time and Chaos.
Depending on what phone you're using, and what CRM, the sync cost(s) are different. Like with Outlook to Android I think it's a $49.95 one-time fee, or $14.95 per quarter. To sync with Chaos software it uses their cloud service which is also $14.95 per quarter. Most are the same, but a couple are a bit more.