chore: Add download info and IzzyOnDroid badge to readme

README.md

@@ -1,18 +1,22 @@
 ![Feature graphic](.github/repo_photos/banner.png)
 
-## About
+## About 🍅
+
+---
+
+<div align="center">
 
 Tomato is a minimalist Pomodoro timer for Android based on Material 3 Expressive.
 
-### Features
+<p>
+  <a href="https://apt.izzysoft.de/fdroid/index/apk/org.nsh07.pomodoro">
+    <img src="https://gitlab.com/IzzyOnDroid/repo/-/raw/master/assets/IzzyOnDroidButtonGreyBorder_nofont.png" width="200">
+  </a>
+</p>
 
-- Simple, minimalist UI based on the latest Material 3 Expressive guidelines
-- Detailed statistics of work/study times in an easy to understand manner
-    - Stats for the current day visible at a glance
-    - Stats for the last week and last month shown in an easy to read, clean graph
-    - Additional stats for last week and month showing at what time of the day you're the most
-      productive
-- Customizable timer parameters
+</div>
+
+---
 
 ## Screenshots
 
@@ -25,6 +29,38 @@ Tomato is a minimalist Pomodoro timer for Android based on Material 3 Expressive
   <img src="fastlane/metadata/android/en-US/images/phoneScreenshots/6.png" width="30%">
 </p>
 
+### Features
+
+- Simple, minimalist UI based on the latest Material 3 Expressive guidelines
+- Detailed statistics of work/study times in an easy to understand manner
+    - Stats for the current day visible at a glance
+    - Stats for the last week and last month shown in an easy to read, clean graph
+    - Additional stats for last week and month showing at what time of the day you're the most
+      productive
+- Customizable timer parameters
+
+## Download
+
+- **F-Droid** (recommended): Tomato is not yet available on the official F-Droid repository.
+  Instead, you can currently install it through
+  the [IzzyOnDroid repository](https://apt.izzysoft.de/fdroid/).
+- **Obtainium** (recommended): You can add this GitHub repository
+  on [Obtainium](https://obtainium.imranr.dev/) to get updates directly from GitHub releases. This
+  is the fastest way to install and update Tomato.
+- **GitHub releases**: Alternatively, you can manually download and install APKs from
+  the [Releases](https://github.com/nsh07/Tomato/releases/latest) section of this repo (This
+  method is not recommended, use Obtainium instead).
+
+> [!TIP]
+> To [verify](https://developer.android.com/studio/command-line/apksigner#usage-verify) the APK
+> downloaded from Obtainium/GitHub, use the following signing certificate fingerprints:
+> ```
+> SHA1: B1:4E:17:93:11:E8:DB:D5:35:EF:8D:E9:FB:8F:FF:08:F8:EC:65:08
+> SHA256: 07:BE:F3:05:81:BA:EE:8F:45:EC:93:E4:7E:E6:8E:F2:08:74:E5:0E:F5:70:9C:78:B2:EE:67:AC:86:BE:4C:3D
+> ```
+> The SHA256 and MD5 hashes of the individual APK files are also available in the `checksum.txt`
+> file for each release.
+
 ## Donate
 
 You can support Tomato's development