diff --git a/README.md b/README.md
index 8fc4fe8..556d30e 100644
--- a/README.md
+++ b/README.md
@@ -341,6 +341,12 @@ Steganography
 
 	Tabs and spaces could be representing 1's and 0's and treating them as a binary message... or, they could be whitespace done with [`snow`][snow] or an esoteric programming language interpreter: [https://tio.run/#whitespace](https://tio.run/#whitespace)
 
+* Audio Speed Change (also change pitch)
+
+```
+mplayer -af scaletempo -speed 64 flag.mp3
+``` 
+
 * DNA Codes
 
     When given a sequence with only A, C, G, T , there is an online mapping for these. Try this:
@@ -348,6 +354,14 @@ Steganography
     ![img/dna_codes.png](img/dna_codes.png)
     ![img/genome_coding.jpg](img/genome-coding.jpg)
 
+* Extract Thumbnail (data is covered in original image)
+
+	If you have an image where the data you need is covered, try viewing the thumbnail:
+
+```
+exiftool -b -ThumbnailImage my_image.jpg > my_thumbnail.jpg
+```
+
 * [`snow`][snow]
 
 	A command-line tool for whitespace steganography (see above).
@@ -741,6 +755,16 @@ PNG File Forensics
 	A command-line tool for "checking" a [PNG] image file. Especially good for verifying checksums.
 
 
+* [`pngcsum`](http://www.schaik.com/png/pngcsum/pngcsum-v01.tar.gz)
+
+	Correct the CRC on all of the parts of a [PNG] image file.
+
+
+* [https://github.com/sherlly/PCRT](https://github.com/sherlly/PCRT)
+
+	Utility to try and correct a [PNG] file. **NOTE... this will NOT SAVE your file as new one. YOU HAVE TO SHOW the file (enter y when using the script]) to actually view the new image.**
+
+
 APK Forensics
 ---------------