How Many Times Can I Download A Paid App From The App Store

Yes you should put a copy on both devices as there is no limit on redownloading apps. Even if it was a purchased app on one device, you can redownload it on another device using the same Apple Account without any charge.

In some cases, the in-app purchases can be redownloaded, although this depends on the type of in-app purchase. For example, a consumable such as game tokens used in the game obviously cannot be redownloaded, but an in-app purchase that unlocks a feature such as removing ads can be redownloaded if it does not show up on your device after redownloading the game.

If you can't find or use your in-app purchases - Apple Support

There is no limit on how many times you download the same app. Once purchased, it stays in your purchase list and you can download anytime you need to.

Emmett_1944 wrote:

That sounds great. It seems like there are a lot more IpadOS apps than apps for the Mac. But that big screen on the iMac is hard to beat when you can open two full size windows side by side. Thanks.

That is correct. Developers choose which device they want to offer native support and by far the most common is the iPhone, followed by the iPad, then the Mac. Luckily your Silicon Mac is capable of running many of these apps as well, it is just a little different experience than one designed to take advantage of the Mac screen size natively.