As of the date this comment was written, this App is an informal Beta version. Looking at the developers website gives me the impression that when it goes final it will become a commercial App and will no longer be free. The other software from this developer tends to have a price range of in the neighborhood of $10 to $20., except for a single much older App that is free. The good news is that this developer does not seem to be subscribing to a subscription model. Cost and frequency of upgrades and updates did not seem to be present.
For those unfamiliar with the term 'Beta', it generally means the product is still being tested before a final version release but that most of the serious bugs have been identified and fixed. It is then placed in circulation so that the typical user can use it with the developers hope that any missed bugs will be reported by the user. so that they can be fixed before the final release. The effectively means that the users of a beta version are also its testers .That is why beta versions are most often free as the users are in effect, working for the developer by testing it without pay. With an informal beta, they product is distributed for free to anyone that wants to try it out. They typically have an expiration date, if included will prevent the product from being used without paying for it. Generally if an informal beta user wants the final version they have to buy it like everyone else.
Formal Beta is when specific users are selected to beta test the App, often with test scripts, and document their work with formal write ups of any software bugs discovered. Formal beta testers are sometimes paid for their work.a They generally receive a released copy of the product for free or reduced cost when it goes final.
This comment should not be taken as a criticism of the App or developer. It is only meant to provide the information needed for the user to make an informed decision of what they are actually getting with their download and use, with the fact that if they wish to continue using it beyond the beta period they will likely cost them something.
In this case the developer is being up front about it by indicating it is a beta version on their website. Some developers do not do this which leaves users very surprised when the they are asked to pay for it when finally released if they wish to continue to use it.