@Samed ArifI have found many handymen at local hardware stores.  150 units is a lot of units, it would seem you could keep that person busy with all sorts of different tasks.  

If you have money to burn through then buy all these Guru courses.If you are a fledgling investor you need to keep your cash and try to gain info here with help from others to learn knowledge.You can also go to a book store and also your local library to read up on the basics for free.You just don't want to go for broke too soon paying someone for a system.

I use deal check. it's an app for android devices. it cost me like 10$ and its great. it can upload straight from the MLS or you can input manually.

So the Schalge Encode stores up to 30 codes at one time.

As being a flooring contractor you can go to Lowes, home Depot any box store and find feathering compounds to fill in the grout joints. depending on the grout joint size and depth you may need to put 2 coats down on the floor, between each coat us a scaper and knock down any high spots and repeat the processes.

How about a few flyers in strategic locations (i.e. local grocery stores)? 

This was the approach we used in a condo building where keypads/guests using the August app was a no-go.The August locks work great, especially in San Antonio where the cold weather is (supposed to be) rare. 

Pottsville's downtown had been in decline with lots of empty store fronts but I think the arrow is pointed up with a couple of new restaurants opening up in the downtown and Yuegnling is a large attraction.

Ours was a former utility company that stores transformers on the lot and left behind PCBs. 

This avoids us having to refund app fees that we have not used.