What is GCAM? Is it on playstore?
GCam is popular shortname for Android software
Google Camera, by Google LLC.
Yes, it's in the Google Play Store. However, it's currently only eligible for Google devices, like the Pixel smartphone family. The Store detects device models, or checks lists of devices under your current Google login account, & evaluates if an app is allowed/eligible, & only allows install if so.
(I'm researching it now to evaluate options & if can install on my devices/phones (I want those benefits!). I just recently found out developers have developed app mods/ports, & provided procedures & downloads, so I'm new to GCam for non-Google devices/phones.).
GCam is considered some of the best camera & photo processing software for Android. Most of the high(est?) quality of Google Pixel phone cameras, is because of the software more than the hardware. So the software can potentially benefit any phone camera, where the software can be installed & used (with full or partial functionality of the software, depending on device model & Android version). That is why people want it (perhaps request by feedback to Google to release for more/all Android devices?).
That is why people are listing Android app mods(modifications)/ports/adaptations here, that are made usable (full or partial functionality) on other devices.
These are from 3rd parties other than Google, so not approved & supported by Google. Trustworthiness of these apps can be questionable; this site tends to have more reliable & knowledgeable developers.
To install 3rd party app (app) on Android, at least have to enable in Android Settings to allow install (from sources other than Google Play Store).
Installing the modded/ported apps (app) can be easy/simple to difficult/complicated/technical, depending on the device model & Android version, & how much meets the app (apk) requirements & any extra updates/changes needed.
Some cases can install app directly; other cases may require other installs, even rooting or unlocking the bootloader on the phone or using remote ADB access from a computer (like desktop or laptop).
Appropriate online articles will usually include requirements or procedures.
GCam usually requires a minimum Android version (recent Google version claims needs Android Pie), because requires at least Google Camera 2 API software library/service for Android (which seems included with Android HAL3). Which may be installable on Android version that doesn't have it; some developers have procedures or download apps to install.
To research availability for a device/phone model, search about an app (GCam, or Google Camera), include the device model, & Android; optional terms, install or apk.