Sub btnAPK_Click
Dim Command, Runner As String
Dim StdOut, StdErr As StringBuilder
Dim Result As Int
Dim Ph As Phone
Dim MyPath as string = File.DirRootExternal & "/B4A"
Runner = File.Combine(File.DirInternalCache, "runner")
Command = File.Combine(File.DirInternalCache, "command")
File.WriteString(File.DirInternalCache, "runner", "su < " & Command)
File.WriteString(File.DirInternalCache, "command", "pm install -r "& File.Combine(MyPath, "Your.apk") & CRLF & _
"am start -n " & "b4a.your/b4a.your.main" & CRLF & "Exit") 'Any commands via crlf, and exit at end
StdOut.Initialize
StdErr.Initialize
Result = Ph.Shell("sh", Array As String(Runner), StdOut, StdErr)
Msgbox(StdOut.tostring, "")
End Sub