FastStone Image Viewer, IrfanView, Google Photos, PhotoPrism, Simple Gallery, digiKam, XnView, ImageGlass, XnView MP, nomacs, Movavi Photo Manager, Excire Search, LeafPic Revived, FotoAlbum, eye of MATE, JPEGView, Sunday, vPhoto Smart Gallery, Aperture Gallery are some alternatives to A Photo Manager.