Add about app

Doesn't look great but it's functional...

internal_filesystem/builtin/apps/com.micropythonos.about/META-INF/MANIFEST.JSON

@@ -0,0 +1,24 @@
+{
+"name": "About",
+"publisher": "MicroPythonOS",
+"short_description": "Info about MicroPythonOS",
+"long_description": "Shows current MicroPythonOS version, MicroPython version, build date and other useful info..",
+"icon_url": "https://apps.micropythonos.com/apps/com.micropythonos.helloworld/icons/com.micropythonos.about_0.0.1_64x64.png",
+"download_url": "https://apps.micropythonos.com/apps/com.micropythonos.helloworld/mpks/com.micropythonos.about_0.0.1.mpk",
+"fullname": "com.micropythonos.about",
+"version": "0.0.1",
+"category": "development",
+"activities": [
+    {
+      "entrypoint": "assets/about.py",
+      "classname": "About",
+      "intent_filters": [
+        {
+          "action": "main",
+          "category": "launcher"
+        }
+      ]
+    }
+  ]
+}
+

internal_filesystem/builtin/apps/com.micropythonos.about/assets/about.py

@@ -0,0 +1,21 @@
+from mpos.apps import Activity
+
+import mpos.info
+import sys
+
+class About(Activity):
+
+    def onCreate(self):
+        screen = lv.obj()
+        screen.set_style_border_width(0, 0)
+        screen.set_flex_flow(lv.FLEX_FLOW.COLUMN)
+        screen.set_style_pad_all(mpos.ui.pct_of_display_width(2), 0)
+        label1 = lv.label(screen)
+        label1.set_text(f"MicroPythonOS version: {mpos.info.CURRENT_OS_VERSION}")
+        label2 = lv.label(screen)
+        label2.set_text(f"sys.version: {sys.version}")
+        label3 = lv.label(screen)
+        label3.set_text(f"sys.implementation: {sys.implementation}")
+        label4 = lv.label(screen)
+        label4.set_text(f"sys.platform: {sys.platform}")
+        self.setContentView(screen)