Primer paso de la investigacion. Se aportan el .apk, las carpetas con el apk extraido y el apk descompilado. El archivo API_DOCUMENTATION.md es un archivo donde se anotaran los descubrimientos del funcionamiento de la API, y los .py son scripts para probar la funcionalidad de la API con los métodos que vayamos encontrando. Finalmente, los archivos .js son scripts de Frida para extraer informacion de la APP durante la ejecucion.

apk_decompiled/sources/kotlin/collections/GroupingKt__GroupingJVMKt.java

@@ -0,0 +1,55 @@
+package kotlin.collections;
+
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import kotlin.Metadata;
+import kotlin.PublishedApi;
+import kotlin.SinceKotlin;
+import kotlin.internal.InlineOnly;
+import kotlin.jvm.functions.Function1;
+import kotlin.jvm.internal.Intrinsics;
+import kotlin.jvm.internal.Ref;
+import kotlin.jvm.internal.SourceDebugExtension;
+import kotlin.jvm.internal.TypeIntrinsics;
+
+@Metadata(d1 = {"\u0000&\n\u0000\n\u0002\u0010$\n\u0000\n\u0002\u0010\b\n\u0000\n\u0002\u0018\u0002\n\u0000\n\u0002\u0010%\n\u0002\b\u0003\n\u0002\u0018\u0002\n\u0002\u0010&\n\u0000\u001a0\u0010\u0000\u001a\u000e\u0012\u0004\u0012\u0002H\u0002\u0012\u0004\u0012\u00020\u00030\u0001\"\u0004\b\u0000\u0010\u0004\"\u0004\b\u0001\u0010\u0002*\u000e\u0012\u0004\u0012\u0002H\u0004\u0012\u0004\u0012\u0002H\u00020\u0005H\u0007\u001aZ\u0010\u0006\u001a\u000e\u0012\u0004\u0012\u0002H\u0002\u0012\u0004\u0012\u0002H\b0\u0007\"\u0004\b\u0000\u0010\u0002\"\u0004\b\u0001\u0010\t\"\u0004\b\u0002\u0010\b*\u000e\u0012\u0004\u0012\u0002H\u0002\u0012\u0004\u0012\u0002H\t0\u00072\u001e\u0010\n\u001a\u001a\u0012\u0010\u0012\u000e\u0012\u0004\u0012\u0002H\u0002\u0012\u0004\u0012\u0002H\t0\f\u0012\u0004\u0012\u0002H\b0\u000bH\u0081\bø\u0001\u0000\u0082\u0002\u0007\n\u0005\b\u009920\u0001¨\u0006\r"}, d2 = {"eachCount", "", "K", "", "T", "Lkotlin/collections/Grouping;", "mapValuesInPlace", "", "R", "V", "f", "Lkotlin/Function1;", "", "kotlin-stdlib"}, k = 5, mv = {1, 9, 0}, xi = 49, xs = "kotlin/collections/GroupingKt")
+@SourceDebugExtension({"SMAP\nGroupingJVM.kt\nKotlin\n*S Kotlin\n*F\n+ 1 GroupingJVM.kt\nkotlin/collections/GroupingKt__GroupingJVMKt\n+ 2 Grouping.kt\nkotlin/collections/GroupingKt__GroupingKt\n+ 3 fake.kt\nkotlin/jvm/internal/FakeKt\n+ 4 _Collections.kt\nkotlin/collections/CollectionsKt___CollectionsKt\n*L\n1#1,52:1\n143#2:53\n80#2,4:54\n85#2:59\n1#3:58\n1855#4,2:60\n*S KotlinDebug\n*F\n+ 1 GroupingJVM.kt\nkotlin/collections/GroupingKt__GroupingJVMKt\n*L\n22#1:53\n22#1:54,4\n22#1:59\n48#1:60,2\n*E\n"})
+/* loaded from: classes3.dex */
+class GroupingKt__GroupingJVMKt {
+    @SinceKotlin(version = "1.1")
+    public static final <T, K> Map<K, Integer> eachCount(Grouping<T, ? extends K> grouping) {
+        Intrinsics.checkNotNullParameter(grouping, "<this>");
+        LinkedHashMap linkedHashMap = new LinkedHashMap();
+        Iterator<T> sourceIterator = grouping.sourceIterator();
+        while (sourceIterator.hasNext()) {
+            K keyOf = grouping.keyOf(sourceIterator.next());
+            Object obj = linkedHashMap.get(keyOf);
+            if (obj == null && !linkedHashMap.containsKey(keyOf)) {
+                obj = new Ref.IntRef();
+            }
+            Ref.IntRef intRef = (Ref.IntRef) obj;
+            intRef.element++;
+            linkedHashMap.put(keyOf, intRef);
+        }
+        for (Map.Entry entry : linkedHashMap.entrySet()) {
+            Intrinsics.checkNotNull(entry, "null cannot be cast to non-null type kotlin.collections.MutableMap.MutableEntry<K of kotlin.collections.GroupingKt__GroupingJVMKt.mapValuesInPlace$lambda$4, R of kotlin.collections.GroupingKt__GroupingJVMKt.mapValuesInPlace$lambda$4>");
+            TypeIntrinsics.asMutableMapEntry(entry).setValue(Integer.valueOf(((Ref.IntRef) entry.getValue()).element));
+        }
+        return TypeIntrinsics.asMutableMap(linkedHashMap);
+    }
+
+    @PublishedApi
+    @InlineOnly
+    private static final <K, V, R> Map<K, R> mapValuesInPlace(Map<K, V> map, Function1<? super Map.Entry<? extends K, ? extends V>, ? extends R> f2) {
+        Intrinsics.checkNotNullParameter(map, "<this>");
+        Intrinsics.checkNotNullParameter(f2, "f");
+        Iterator<T> it = map.entrySet().iterator();
+        while (it.hasNext()) {
+            Map.Entry entry = (Map.Entry) it.next();
+            Intrinsics.checkNotNull(entry, "null cannot be cast to non-null type kotlin.collections.MutableMap.MutableEntry<K of kotlin.collections.GroupingKt__GroupingJVMKt.mapValuesInPlace$lambda$4, R of kotlin.collections.GroupingKt__GroupingJVMKt.mapValuesInPlace$lambda$4>");
+            TypeIntrinsics.asMutableMapEntry(entry).setValue(f2.invoke(entry));
+        }
+        return TypeIntrinsics.asMutableMap(map);
+    }
+}