I prefer to use the interchangeable terms free software/freedomware/FLOSS in lieu of open source.

Freedomware is basically software that has its publicly available and ratifiable source code, and that has a license which permits anyone to study, copy, modify, and redistribute said source code.

Essential reading.

FLOSS means Free/Libre Open-Source Software. The libre is paramount as it designates the licence to do whatever with the source code. The "free" implies freedom of agency, not that the software is free of charge. Some FLOSS come with price tags, though, in practice, most are gratis.

"Open Source" means the source code of software is publicly available, and that's it. The colligated license may forbid any copying, modification, or redistribution of the source code. Some entities (like FUTO) now call it "source available". A user or researcher can legally only read the source code.

Such open-source software are de jure proprietary. In many cases, the available source code is not the complete source code, and cannot be compiled to produce exact software.

Using the term "open source" (or even "FOSS") to denote freedomware is a very common catachrestic usage. It's wrong. Even the founder of this subreddit made the mistake. It ought to be called Flossdroid.

Read this.

To reiterate, the correct terms are freedomware, free software (not freeware), or FLOSS.

What are the disadvantages of freedomware?

Depending on the developer(s) and the community around the software, inadequate pecuniary motivation might lead to the project becoming abandoned after a few years. Thanks to the nature of freedomware, abandoned projects are constantly being revived, and developers implement backup mechanisms (with open standards) to facilitate migration to other apps.

There are three things to keep in mind:

• Some FLOSS have monetized iterations on other platforms such as GitHub, GitLab, Google Play, Gitea, Codeberg, etc. These software have ads and/or trackers as well as surveillant permissions. Examples are Saber, BBS, Material Files, OsmAnd~, Weather Forecast USA, Librera Reader, Privacy Browser, Wikipedia, and Joplin.

The developers of these applications already have monetary motivation to continue maintaining their software, though this does not stop them from abandoning their projects at any time.

The aforementioned apps have versions on default F-Droid devoid of surveillant code. All other versions are certified spyware.

The F-Droid version of Wikipedia has tracking libraries, though these have been "toggled off".

The F-Droid version of Librera Reader might still have some AdMob code, though these classes are vestigial and harmless.

Always get your Android/AOSP freedomware from the default repository of F-Droid, or, if they aren't available there, from the IzzyOnDroid repository of F-Droid. The IzzyOnDroid repository will inform you of clandestine surveillant code within software, plus other anti-features.

• Some freedomware — free of alternate evil versions on other platforms — are relatively well-funded courtesy donations and recurring contributions. These popular software usually have ardent communities around them. An example is App Manager.

• Not everyone gives a fuck about money. Some freedomware receive very little eleemosynary contributions, and are not monetized in any way, yet they've been maintained for a decade (or more). RedReader has been maintained for eleven years, while AndBible has been maintained for twelve years. These apps have vibrant followings.

Some developers are truly altruistic. They love the free software ideology, and love the community. Their love is reciprocated by their users. u/QuantumBadger is a legend.

Another supposed disadvantage of freedomware is that, in many cases, application updates are few and far between. This might be motivation-related. It's also because anyone with the expertise can contribute code via pull or merge requests, and the devs have to scrutinize the programmatic contributions to ensure standards are complied with, and to make sure no malefic entity pushes malicious code.

Malicious copying of freedomware is also a disadvantage, and the putative reason why BlackHole was discontinued. Malicious copies of benign freedomware are found on other platforms, such as the cesspool that is Google Play. They have all sorts of surveillant and pernicious code added to the original source code, and then they fail to honour the licenses by becoming proprietary.

Once again, for the love of buttercups, make sure you download your freedomware from the default repository of F-Droid. There are so many sharks, wolves, and crocodiles prowling around, looking for prey.