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/internal/UProgressionUtilKt.java

@@ -0,0 +1,61 @@
+package kotlin.internal;
+
+import kotlin.Metadata;
+import kotlin.PublishedApi;
+import kotlin.SinceKotlin;
+import kotlin.UInt;
+import kotlin.ULong;
+
+@Metadata(d1 = {"\u0000 \n\u0000\n\u0002\u0018\u0002\n\u0002\b\u0005\n\u0002\u0018\u0002\n\u0002\b\u0006\n\u0002\u0010\b\n\u0000\n\u0002\u0010\t\n\u0002\b\u0002\u001a'\u0010\u0000\u001a\u00020\u00012\u0006\u0010\u0002\u001a\u00020\u00012\u0006\u0010\u0003\u001a\u00020\u00012\u0006\u0010\u0004\u001a\u00020\u0001H\u0002¢\u0006\u0004\b\u0005\u0010\u0006\u001a'\u0010\u0000\u001a\u00020\u00072\u0006\u0010\u0002\u001a\u00020\u00072\u0006\u0010\u0003\u001a\u00020\u00072\u0006\u0010\u0004\u001a\u00020\u0007H\u0002¢\u0006\u0004\b\b\u0010\t\u001a'\u0010\n\u001a\u00020\u00012\u0006\u0010\u000b\u001a\u00020\u00012\u0006\u0010\f\u001a\u00020\u00012\u0006\u0010\r\u001a\u00020\u000eH\u0001¢\u0006\u0004\b\u000f\u0010\u0006\u001a'\u0010\n\u001a\u00020\u00072\u0006\u0010\u000b\u001a\u00020\u00072\u0006\u0010\f\u001a\u00020\u00072\u0006\u0010\r\u001a\u00020\u0010H\u0001¢\u0006\u0004\b\u0011\u0010\t¨\u0006\u0012"}, d2 = {"differenceModulo", "Lkotlin/UInt;", "a", "b", "c", "differenceModulo-WZ9TVnA", "(III)I", "Lkotlin/ULong;", "differenceModulo-sambcqE", "(JJJ)J", "getProgressionLastElement", "start", "end", "step", "", "getProgressionLastElement-Nkh28Cs", "", "getProgressionLastElement-7ftBX0g", "kotlin-stdlib"}, k = 2, mv = {1, 9, 0}, xi = 48)
+/* loaded from: classes3.dex */
+public final class UProgressionUtilKt {
+    /* renamed from: differenceModulo-WZ9TVnA, reason: not valid java name */
+    private static final int m1321differenceModuloWZ9TVnA(int i, int i4, int i5) {
+        int remainderUnsigned = Integer.remainderUnsigned(i, i5);
+        int remainderUnsigned2 = Integer.remainderUnsigned(i4, i5);
+        int compareUnsigned = Integer.compareUnsigned(remainderUnsigned, remainderUnsigned2);
+        int m211constructorimpl = UInt.m211constructorimpl(remainderUnsigned - remainderUnsigned2);
+        return compareUnsigned >= 0 ? m211constructorimpl : UInt.m211constructorimpl(m211constructorimpl + i5);
+    }
+
+    /* renamed from: differenceModulo-sambcqE, reason: not valid java name */
+    private static final long m1322differenceModulosambcqE(long j4, long j5, long j6) {
+        long remainderUnsigned = Long.remainderUnsigned(j4, j6);
+        long remainderUnsigned2 = Long.remainderUnsigned(j5, j6);
+        int compareUnsigned = Long.compareUnsigned(remainderUnsigned, remainderUnsigned2);
+        long m290constructorimpl = ULong.m290constructorimpl(remainderUnsigned - remainderUnsigned2);
+        return compareUnsigned >= 0 ? m290constructorimpl : ULong.m290constructorimpl(m290constructorimpl + j6);
+    }
+
+    @SinceKotlin(version = "1.3")
+    @PublishedApi
+    /* renamed from: getProgressionLastElement-7ftBX0g, reason: not valid java name */
+    public static final long m1323getProgressionLastElement7ftBX0g(long j4, long j5, long j6) {
+        if (j6 > 0) {
+            return Long.compareUnsigned(j4, j5) >= 0 ? j5 : ULong.m290constructorimpl(j5 - m1322differenceModulosambcqE(j5, j4, ULong.m290constructorimpl(j6)));
+        }
+        if (j6 < 0) {
+            return Long.compareUnsigned(j4, j5) <= 0 ? j5 : ULong.m290constructorimpl(j5 + m1322differenceModulosambcqE(j4, j5, ULong.m290constructorimpl(-j6)));
+        }
+        throw new IllegalArgumentException("Step is zero.");
+    }
+
+    @SinceKotlin(version = "1.3")
+    @PublishedApi
+    /* renamed from: getProgressionLastElement-Nkh28Cs, reason: not valid java name */
+    public static final int m1324getProgressionLastElementNkh28Cs(int i, int i4, int i5) {
+        if (i5 > 0) {
+            if (Integer.compareUnsigned(i, i4) < 0) {
+                return UInt.m211constructorimpl(i4 - m1321differenceModuloWZ9TVnA(i4, i, UInt.m211constructorimpl(i5)));
+            }
+        } else {
+            if (i5 >= 0) {
+                throw new IllegalArgumentException("Step is zero.");
+            }
+            if (Integer.compareUnsigned(i, i4) > 0) {
+                return UInt.m211constructorimpl(i4 + m1321differenceModuloWZ9TVnA(i, i4, UInt.m211constructorimpl(-i5)));
+            }
+        }
+        return i4;
+    }
+}