Worked through, added tests for everything

src/MyCounter-Tests/CounterTest.class.st

@@ -4,7 +4,7 @@ This class contains tests for the Counter class
 Class {
 	#name : #CounterTest,
 	#superclass : #TestCase,
-	#category : #MyCounter
+	#category : #'MyCounter-Tests'
 }
 
 { #category : #tests }

src/MyCounter-Tests/package.st

@@ -0,0 +1 @@
+Package { #name : #'MyCounter-Tests' }

src/MyCounter/Counter.class.st

@@ -16,6 +16,11 @@ Class {
 	#category : #MyCounter
 }
 
+{ #category : #accessing }
+Counter class >> startingAt: val [
+  ^ self new count: val; yourself
+]
+
 { #category : #accessing }
 Counter >> count [
 	"returns the current count"
@@ -29,3 +34,29 @@ Counter >> count: val [
 	^ val
 	
 ]
+
+{ #category : #API }
+Counter >> decrement [
+	"decrease the value of count by 1"
+	count := count - 1.
+	^ self
+]
+
+{ #category : #API }
+Counter >> increment [ 
+	"updates the count by 1"
+	count := count + 1.
+	^ self
+]
+
+{ #category : #initialization }
+Counter >> initialize [ 
+	"Set the initial value to 0"
+	count := 0
+]
+
+{ #category : #printing }
+Counter >> printOn: aStream [
+	super printOn: aStream.
+	aStream nextPutAll: ' with value: ', count printString.
+]