-Firefox Native Search engines: The same searchs engines that are avalible in the Search Bar. Only avalible in Firefox Desktop
-DivFind search engines: Search engines manually configured inside the addon. Avalible in all platforms
-Firefox can do searchs from context menu, widget and Hotkey with Native and DivFind search engines
-Fennec/Firefox for Android: Can do searchs in long clikcs with DivFind search engines
-Thunderbird: Can do searchs from context menus with DivFind search engines. EXPERIMENTAL
-SeaMonkey: Can do searchs from context menus with DivFind search engines. EXPERIMENTAL
Note that SeaMonkey and Thunderbird are under EXPERIMENTAL. This means that may work or not.