In line with the objectives of QEP#236, which seeks to align and unify all geometry and topology verification/ validation methods, the Geometry Checker has now been integrated into the QGIS Processing Toolbox.
These algorithms have been added to the "Check Geometry" and "Fix Geometry" categories accordingly, and each algorithm maintains a consistent experience having a single input layer and two output layers.
For check processing algorithms, the outputs are:

• a layer of the same type as the input layer with erroneous geometries only
• a point layer with the error locations and information (feature id, part, and vertex number, etc.)

For fix processing algorithms, the outputs are:

• a fixed layer of the same type as the input layer with corrected features according to the the chosen method
• a point layer with the error locations and a report about the fix (fixed or not, and a message about the processed feature)